Zodios request parameter type inference not working as expected

[vmgarcia]

The type inference generated from the code below does not work as expected.

export const parameters = makeParameters([
  {
    name: 'userId',
    description: "The user's id.",
    schema: userSchema.pick({ id: true }),
    type: 'Body',
  },
  {
    name: 'newTask',
    description: 'The definition of the new task being created.',
    schema: taskSchema.omit({ id: true, createdAt: true }),
    type: 'Body',
  },
]);

export const createTask = makeEndpoint({
  method: 'post',
  path: '/tasks',
  requestFormat: 'json',
  response: taskSchema,
  alias: 'createTask',
  description: 'Create a new task for a user',
  parameters,
});

export const taskRouter = zodiosRouter(taskApi);

taskRouter.post('/tasks', async (req, res) => {
  const { userId, newTask } = req.body;
  const nextId = uuidv4();

  const task: Task = {
    ...newTask,
    id: nextId,
  };
  res.json(task);
});

I expect req.body to be equivalent to

type body = {
  userId: z.infer<userSchema.pick({ id: true })>;
  newTask: z.infer<taskSchema.omit({ id: true, createdAt: true })>
 };

Instead it's

type body = z.infer<userSchema.pick({ id: true })> | z.infer<taskSchema.omit({ id: true, createdAt: true })>

I'm not sure if this is the intended behavior, it's not intuitive or explained in the docs.

As a workaround I'm just using

export const parameters = makeParameters([
  {
    name: 'body',
    description: 'The body of the create task request.',
    schema: z.object({
      userId: userSchema.pick({ id: true }),
      newTask: taskSchema.omit({ id: true, createdAt: true }),
    }),
    type: 'Body',
  },
]);

[ecyrbe]

Oh, body should only be declared once if you want to have them merged. The double declaration is for unions (one body or another). You can declare it like this :

export const parameters = makeParameters([
  {
    name: 'UserNewTask',
    description: "'The definition of the new task being created",
    schema: z.object({ userId: z.number()}).merge(askSchema.omit({ id: true, createdAt: true })),
    type: 'Body',
  }
]);

would you like to propose an improvement to documentation to explain this behaviour with more exemples ? Improving the docs is straightforward. All is in markdown in /website directory. I would love to have users help improve the docs with concrete exemples.